On the spur of the moment, we decided to stay at this campsite and ended up staying two nights. The sites were clean with good flat spots for tents. They had fire pits, clean toilets, and very nice campsite hosts. The lake is little but charming. There is a trail that runs around the lake which is a nice, easy hike. My boys loved riding their bikes around the campground (which is small enough that you can see them even if they are on the other side of the lake). There were kids kayaking and swimming in the lake and about a dozen people fishing. The only downside, in my opinion, was that the sites weren't very private; we could see and hear all of our neighbors. This is a good spot for families with kids.
Lost Lake is pretty famous and didn't disappoint. Large but private camp sites on a gorgeous lake with a quintessential view of Mt. Hood. You can rent kayaks, canoes, fishing poles, etc. Lots of walk-in sites, however, this spot is very popular so in the high season, you may have the best luck going mid-week or early in the morning to claim a spot.
It's not the most scenic site, but worked out great. There is no water, however, so you need to be prepared for that. The 90 is a rough road - it has tons of really bad dips. Someone told us that because of this, not many horse trailers travel to this campsite anymore. Therefore it wasn't smelly or buggy at all. Really comfortable actually. It was a clear night with a full moon and we had a great time.
This was a beautiful, heavily-shaded campsite just off the river and by a great hiking trail. The kids were able to collect rocks near the river and explore and the forest. You could hear the river from site #8, which made for nice background noise. One day we hiked the Salmon River Trail, which was gorgeous. We went south - the trail goes through an old growth forest along the river. It's amazing.